From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Courbot Subject: Re: [PATCH v6 1/4] Runtime Interpreted Power Sequences Date: Thu, 13 Sep 2012 15:08:23 +0900 Message-ID: <1464760.6eqxJ2IzZ2@percival> References: <1347443867-18868-1-git-send-email-acourbot@nvidia.com> <1347443867-18868-2-git-send-email-acourbot@nvidia.com> <1347515139.7471.7.camel@lappyti> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1347515139.7471.7.camel@lappyti> Sender: linux-kernel-owner@vger.kernel.org To: Tomi Valkeinen Cc: Stephen Warren , Thierry Reding , Simon Glass , Grant Likely , Rob Herring , Mark Brown , Anton Vorontsov , David Woodhouse , Arnd Bergmann , Leela Krishna Amudala , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fbdev@vger.kernel.org" , "devicetree-discuss@lists.ozlabs.org" , "linux-pm@vger.kernel.org" , "linux-doc@vger.kernel.org" List-Id: linux-tegra@vger.kernel.org On Thursday 13 September 2012 13:45:39 Tomi Valkeinen wrote: > * PGP Signed by an unknown key > > On Wed, 2012-09-12 at 18:57 +0900, Alexandre Courbot wrote: > > > Some device drivers (panel backlights especially) need to follow precise > > sequences for powering on and off, involving gpios, regulators, PWMs > > with a precise powering order and delays to respect between each steps. > > These sequences are board-specific, and do not belong to a particular > > driver - therefore they have been performed by board-specific hook > > functions to far. > > > The sequences are not board-specific, they are device (backlight, etc.) > specific. The sequences have been handled in board-specific hook > functions so far because there hasn't been proper drivers for the > devices. > > If I were to take the same panel (and backlight) you have and install it > on my board, I would need the same power sequence. You could also have power sequences that control a set of GPIOs for an external interface (and would then be more board-specific), but you are right that for most of the case power seqs apply to devices and this statement is misleading. I will fix that in the commit message and wherever this might appear. Alex.